Association between serum ferritin and bone turnover marker levels in type 2 diabetes mellitus patients with non-alcoholic fatty liver disease.

Objective: To investigate the correlation between serum ferritin (SF) and bone turnover markers in type 2 diabetes mellitus (T2DM) patients with non-alcoholic fatty liver disease (NAFLD).

Methods: Seven hundred and forty-two people with T2DM were selected. Serum bone turnover markers: osteocalcin (OC), type I procollagen N-terminal peptide (PINP), β-I type collagen carboxy-terminal peptide (β-CTx), and 25-hydroxyvitamin D3 (25-[OH]-D) levels were detected. High SF (HF) was defined as the indicated SF levels above 400 ng/mL in males and more than 150 ng/mL in females. Patients were divided into four groups: T2DM+normal SF (non-HF); T2DM+high SF (HF); T2DM+NAFLD+non-HF; andT2DM+NAFLD+HF. Relationships between SF and bone turnover markers were analyzed.

Results: Compared with the T2DM+non-HF group, β-CTx levels were higher in the T2DM+HFgroup. Compared with the T2DM+NAFLD+non-HF group, β-CTx levels were increased and 25-(OH)-D levels decreased in the T2DM+NAFLD+HF group (all p < 0.05). SF was positively correlated with β-CTx [β = 0.074; 95% CI (0.003, 0.205)] and negatively correlated with 25-(OH)-D [β=-0.108; 95%CI (-0.006, -0.001)]. Compared with the T2DM+non-HF group, an independent positive correlation was found between β-CTx and SF in the T2DM+NAFLD+HF group [OR = 1.002; 95% CI (1.001, 1.004)]. Among males, SF was positively correlatedwith β-CTx [β = 0.114; 95% CI (0.031, 0.266)]. SF was negatively correlated with 25-(OH)-D levels in both male and female patients [β=-0.124; 95% CI (0.007,0.001) and β=-0.168; 95% CI (-0.012, -0.002)]. Among those >50 years of age and postmenopausal females, SF was negatively correlated with 25-(OH)-D levels [β=-0.117; 95% CI (-0.007, -0.001) and β=-0.003; 95% CI (-0.013, -0.003)].

Conclusion: SF level was positively correlated with β-CTx in T2DM patients with NAFLD, which may promote bone resorption and increase the risk of bone loss.